View Issue Details

IDProjectCategoryView StatusLast Update
0001858FreeCADBugpublic2022-01-24 19:16
ReporterNikB Assigned Toshoogen  
Status acknowledgedResolutionopen 
Platformx86OSWindowsOS Version8
Product Version0.14 
Target Version0.20 
Summary0001858: Loft tool incorrect result with rotated ellipses (Upstream OCC bug)
DescriptionLoft tool gives unexpected result when using identical ellipses rotated. One end edge as expected, but other has scolloping, concave or convex dependent on two or more ellipses.
Tags#ready-for-migration, Bountysource Potential, bump, OCC Bug, OCC NotOnRoadmap, upstream
FreeCAD Information



2014-12-16 21:37


prop001.FCStd (Attachment missing)


2014-12-17 10:14

developer   ~0005400

Last edited: 2014-12-17 10:32

reproduceable in DRAWEXE of OCCT 6.8.1-dev
reported as


2017-08-22 11:47

administrator   ~0009990

Still reproducible on OCCT 7.1 and upstream isn't on the roadmap. Requires bump.


2018-10-19 13:36

administrator   ~0012071

@adbdullah would you be interested in bumping the upstream ticket in the hopes that it may be added to the OCC roadmap ?


2018-11-11 06:18

manager   ~0012173

Original attachment is missing, and the attached files in the OCCT bug tracker can't be downloaded.

A loft between three ellipses rotated 90 degrees from each other appear fine in FC 0.18-dev with latest OCCT 7.3.0...


2018-11-12 00:47

administrator   ~0012179

What should be we do about this ticket then?


2018-11-12 02:55

manager   ~0012180

Maybe the OCCT bug tracker requires to be registered to download. Since @abdullah has an account, we could ask him to upload the files here so we could check with FreeCAD compiled with latest OCCT. From what I understand of the posted DRAWEXE script (in the upstream bug, "Steps to reproduce"), it reads from brep files that are probably included in the zip archive.


2018-11-13 17:51

manager   ~0012191

Files are attached. I will indicate that the FC project is monitoring this ticket and whether it will be assigned to a roadmap. (1,713 bytes)
loft-el1.png (12,170 bytes)   
loft-el1.png (12,170 bytes)   


2018-11-14 19:06

manager   ~0012196


Bugnote #0081082 added by MSV (developer) 2018-11-14 10:12

Dear abdullah, OCC has no fonds to solve this bug in the nearest future without external investment or contribution. You are welcome to propose your fix if you can.


2018-11-14 19:08

manager   ~0012197

Unfortunately it is a too big shoe for my feet.


2018-11-15 01:53

manager   ~0012198

Thanks, abdullah. I imported the 3 brep files into FreeCAD and created a Part Loft. I'm attaching it for future reference. The issue indeed persists with OCC 7.3.0. Ellipses are rotated only a few degrees, I had tried 90 degrees between each ellipse and that worked.

I also tried a sweep with a straight line from (0,0,0) to (0,0,20) as path; same issue.

That's a bummer on OCC's reply...
FC_issue_0001858.fcstd (13,674 bytes)


2022-03-03 13:55

administrator   ~0017149

This ticket has been migrated to GitHub as issue 6318.

Issue History

Date Modified Username Field Change
2014-12-16 21:37 NikB New Issue
2014-12-16 21:37 NikB File Added: prop001.FCStd
2014-12-17 10:14 shoogen Note Added: 0005400
2014-12-17 10:14 shoogen Assigned To => shoogen
2014-12-17 10:14 shoogen Status new => acknowledged
2014-12-17 10:32 shoogen Note Edited: 0005400
2014-12-17 10:32 shoogen Severity major => minor
2014-12-17 10:33 shoogen Tag Attached: OCC Bug
2017-01-15 04:34 Kunda1 Tag Attached: upstream
2017-01-27 01:26 Kunda1 Tag Attached: bump
2017-08-22 11:47 Kunda1 Note Added: 0009990
2017-08-22 11:52 Kunda1 Tag Attached: OCC Unscheduled
2017-08-22 11:56 Kunda1 Tag Renamed OCC Unscheduled => OCC NotOnRoadmap
2018-10-19 13:36 Kunda1 Note Added: 0012071
2018-11-11 06:18 normandc Note Added: 0012173
2018-11-12 00:47 Kunda1 Note Added: 0012179
2018-11-12 02:55 normandc Note Added: 0012180
2018-11-13 17:51 abdullah File Added:
2018-11-13 17:51 abdullah File Added: loft-el1.png
2018-11-13 17:51 abdullah Note Added: 0012191
2018-11-14 19:06 abdullah Note Added: 0012196
2018-11-14 19:08 abdullah Note Added: 0012197
2018-11-15 01:53 normandc File Added: FC_issue_0001858.fcstd
2018-11-15 01:53 normandc Note Added: 0012198
2018-11-22 11:10 Kunda1 Tag Attached: potentialbounty
2018-12-24 12:52 Kunda1 Tag Renamed potentialbounty => Bountysource Potential
2020-01-14 17:39 Kunda1 Summary Loft tool incorrect result with rotated ellipses => Loft tool incorrect result with rotated ellipses (Upstream OCC bug)
2021-02-06 06:49 abdullah Target Version => 0.20
2022-01-24 19:16 Kunda1 Tag Attached: #ready-for-migration